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ST. CLAIR BEACH

TO TUB EDITOR. Sir,—lt has been suggested on more than ono occasion that if a groyne were built from Black Head towards White Island, such groyne would not only prevent further- denudation, but would also be tho means of reclaiming the beach at St. Clair. In my opinion if that scheme is put into operation only disastrous results will follow, and before any work of a practical nature is commenced those- in authority would do well to give serious consideration to tho whole" question. I base my objections on the following reasons:—ln the first pla.ee, it is well known to those who take n,n interest in hydrography that any projection, such as a headland spit, a reef, etc., thrown across the natural How of a tidal stream will, divert arid divide such stream when brought into opposition with tho abovenamed objects; thus we find that tho action of the flood tide sweeping the coast in a northerly direction is brought into conflict with Black Head, and is there diverted and divided into .two forces—-ono commonly known as an eddy tide, or what tho engineer calls in his report a littoral current, eddies round the rocks; but it is only a negligible quantity, and so far as St. Clair Beach is concerned need not be seriously reckoned with. The full strength of the current docs not again touch the beach until well down towards St. Kilda. Proof of this -can be econ after each Hood tide, for notwithstanding the. fact that tho last-named portion of the beach is far more exposed than the sheltered end. and is therefore subjected to heavier v. eatficr conditions, wo find that the sand is taken from tho sheltered end and piled up on tho more exposed portion. Tho reason for the sand accumulating and remaining there is to bo found in (ho fact that the powerful current contained in the flood tide is brought into opposition with the under-tow and back-wash, and so acts as a deterrent to the sand being carried out to sea again. Therefore any extension added to Black Hoad will' only divert tho current further seawards, and any sand that might be deposited on tho beach would be carried far beyond the place where it is most required.' In conclusion I. would like to suggest, as one who i has studied this subject from all points, ; that it would Us well for man to begin ; whore Nature has left oft', and that is, i build your groyne from St. Kilda.—-I am, i etc., ’ . ' I Infkhioheii xe rejictas. May 31. ____ 1

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Permanent link to this item

https://paperspast.natlib.govt.nz/newspapers/ESD19210602.2.13

Bibliographic details

Evening Star, Issue 17677, 2 June 1921, Page 2

Word Count
432

ST. CLAIR BEACH Evening Star, Issue 17677, 2 June 1921, Page 2

ST. CLAIR BEACH Evening Star, Issue 17677, 2 June 1921, Page 2